Bottom Line:
Carboxymethyl cellulase (CMCase) provides a key opportunity for achieving tremendous benefits of utilizing rice straw as cellulosic biomass.Out of total 80 microbial isolates from different ecological niches one bacterial strain, identified as Bacillus sp. 313SI, was selected for CMCase production under stationary as well as shaking conditions of growth.The present study provides the useful data about the optimized conditions for CMCase production by Bacillus sp. 313SI from pretreated rice straw.

ABSTRACTCarboxymethyl cellulase (CMCase) provides a key opportunity for achieving tremendous benefits of utilizing rice straw as cellulosic biomass. Out of total 80 microbial isolates from different ecological niches one bacterial strain, identified as Bacillus sp. 313SI, was selected for CMCase production under stationary as well as shaking conditions of growth. During two-stage pretreatment, rice straw was first treated with 0.5 M KOH to remove lignin followed by treatment with 0.1 N H2SO4 for removal of hemicellulose. The maximum carboxymethyl cellulase activity of 3.08 U/mL was obtained using 1% (w/v) pretreated rice straw with 1% (v/v) inoculum, pH 8.0 at 35°C after 60 h of growth under stationary conditions, while the same was obtained as 4.15 U/mL using 0.75% (w/v) pretreated substrate with 0.4% (v/v) inoculum, pH 8.0 at 30°C, under shaking conditions of growth for 48 h. For maximum titre of CMCase carboxymethyl cellulose was optimized as the best carbon source under both cultural conditions while ammonium sulphate and ammonium nitrate were optimized as the best nitrogen sources under stationary and shaking conditions, respectively. The present study provides the useful data about the optimized conditions for CMCase production by Bacillus sp. 313SI from pretreated rice straw.

fig5: Effect of temperature on carboxymethyl cellulase enzyme production by Bacillus sp. 313SI under stationary and shaking conditions of growth. Values in figure are means of three replicates with standard deviation.

Mentions:
The effect of temperature varying between 20°C and 50°C on production of carboxymethyl cellulase enzyme was studied. Bacillus sp. 313SI showed maximum carboxymethyl cellulase enzyme activity of 2.85 ± 0.05 U/mL under stationary conditions at 35°C and 3.70 ± 0.06 U/mL under shaking conditions at 30°C as shown in Figure 5. The ANOVA for the data on CMCase as a function of variation due to different temperatures under stationary conditions (F = 115.0; P < 0.0001) and shaking conditions (F = 184.4; P < 0.0001) is statistically significant. These results are close to those of Kanmani et al. [21] who found that the carboxymethyl cellulase enzyme produced by Bacillus pumilis showed the optimum temperature of 35°C. Rastogi et al. [41] reported two strains DUSELR7 and DUSELR13 as mesophilic carboxymethyl cellulase enzyme producer at 37°C.

fig5: Effect of temperature on carboxymethyl cellulase enzyme production by Bacillus sp. 313SI under stationary and shaking conditions of growth. Values in figure are means of three replicates with standard deviation.

Mentions:
The effect of temperature varying between 20°C and 50°C on production of carboxymethyl cellulase enzyme was studied. Bacillus sp. 313SI showed maximum carboxymethyl cellulase enzyme activity of 2.85 ± 0.05 U/mL under stationary conditions at 35°C and 3.70 ± 0.06 U/mL under shaking conditions at 30°C as shown in Figure 5. The ANOVA for the data on CMCase as a function of variation due to different temperatures under stationary conditions (F = 115.0; P < 0.0001) and shaking conditions (F = 184.4; P < 0.0001) is statistically significant. These results are close to those of Kanmani et al. [21] who found that the carboxymethyl cellulase enzyme produced by Bacillus pumilis showed the optimum temperature of 35°C. Rastogi et al. [41] reported two strains DUSELR7 and DUSELR13 as mesophilic carboxymethyl cellulase enzyme producer at 37°C.

Bottom Line:
Carboxymethyl cellulase (CMCase) provides a key opportunity for achieving tremendous benefits of utilizing rice straw as cellulosic biomass.Out of total 80 microbial isolates from different ecological niches one bacterial strain, identified as Bacillus sp. 313SI, was selected for CMCase production under stationary as well as shaking conditions of growth.The present study provides the useful data about the optimized conditions for CMCase production by Bacillus sp. 313SI from pretreated rice straw.

ABSTRACTCarboxymethyl cellulase (CMCase) provides a key opportunity for achieving tremendous benefits of utilizing rice straw as cellulosic biomass. Out of total 80 microbial isolates from different ecological niches one bacterial strain, identified as Bacillus sp. 313SI, was selected for CMCase production under stationary as well as shaking conditions of growth. During two-stage pretreatment, rice straw was first treated with 0.5 M KOH to remove lignin followed by treatment with 0.1 N H2SO4 for removal of hemicellulose. The maximum carboxymethyl cellulase activity of 3.08 U/mL was obtained using 1% (w/v) pretreated rice straw with 1% (v/v) inoculum, pH 8.0 at 35°C after 60 h of growth under stationary conditions, while the same was obtained as 4.15 U/mL using 0.75% (w/v) pretreated substrate with 0.4% (v/v) inoculum, pH 8.0 at 30°C, under shaking conditions of growth for 48 h. For maximum titre of CMCase carboxymethyl cellulose was optimized as the best carbon source under both cultural conditions while ammonium sulphate and ammonium nitrate were optimized as the best nitrogen sources under stationary and shaking conditions, respectively. The present study provides the useful data about the optimized conditions for CMCase production by Bacillus sp. 313SI from pretreated rice straw.